Fault Tolerant Task Re-Assignation in a Parallel-Inverters System

In this paper a task re-assignation for a Parallel-Inverters System integrated by a Master-Inverter and n Slave-Inverters is proposed such that the required power is holding if a fault occurs in sensors and actuators of the system. The considered fault scenario is a fault in the Master-Inverter or in any of the Slave-Inverters. The diagnosis capability of the system is made using the structural analysis based on graph tools. On the base of the faults signature and the redundant graphs, the Analytical Redundancy Relations are obtained for the system with two Slave-Inverters. The fault tolerant scheme which supplies the required power at the load in fault conditions is achieved changing only the references signals of the control loops for the Master-Inverter and each Slave-Inverter, and disconnecting the faulty inverter of the whole system. Thus, the addition of a reconfiguration logic with a Fault Detection and Isolation system to the conventional Parallel-Inverters System allows to satisfy the power supply at the load in fault conditions. Simulation results show the potentiality of the simple task re-assignation in the whole system.